Unloader valves or “regulators”, as they are sometimes referred to, direct the flow of water exiting a pump. In particular, unloader valves are designed to redirect the flow of water from the outlet of the pump, through the unloader valve, and back to the inlet side of the pump to prevent dangerously high pressure from building in the pump, and when activated through a separate outlet or exhaust. Unloader valves are often required for high pressure pumping applications for quickly and efficiently regulating excess pressure created by the high pressure pump. Types of unloader valves include “trapped pressure” valves, which are activated by building pressure within the valve assembly, and “flow actuated” valves, which are activated by a decrease in fluid flow. Examples of when unloader valves or regulators are required may include instances where a high pressure pump is continuously operated, or in instances where the pressure needs to be regulated to avoid damage to the high pressure pump, its component parts, or to the system with which the high pressure pump is associated.
In the past, unloader valves had to be designed for each type of pump for which they were employed. This was true not only for the size of the pump, and the location of the couplings of the unloader valve, but also for the minimum and maximum flow rates allowed by the unloader valve. As a result of their custom nature, such unloader valves known in the prior art are extremely sensitive to adjustment, and also sensitive to the precise sizing and locations of couplings of the unloader valve to the particular pump. This is due at least in part to the relatively high pressures experienced by the unloader valves during operation, and the couplings between the unloader valve and the pump. For a further description of problems associated with unloader valves and regulators known in the art, please refer to U.S. Pat. No. 3,834,413, which is incorporated by reference herein in its entirety. U.S. Pat. Nos. 5,396,918, 5,419,365, and 6,478,643 are also incorporate by reference herein in their entireties.
Prior art unloader valves and related “regulating” devices are limited in the variety and types of pumps and high pressure pumps that they accommodate. More specifically, if the inlet and outlet for the pump are not aligned within the range of locations of the fittings for the particular pumps requiring the unloader valve, the unloader valve will not allow coupling with and therefore will not function with the particular pump. It is common for pumps to have inlet and outlet connections that are spaced both horizontally and vertically apart from one another, and this spacing often differs from one pump to the next. Thus, these prior art unloader valves do not accommodate a wide variety of different sized high pressure pumps and other similar devices, and generally experience other problems associated with prior art unloader valves.